Refrigerators are available in many styles, with the most common styles including both a refrigerator compartment and a freezer compartment, which may be side-by-side or one on top of the other. Controls regulate the temperature in each compartment, but otherwise there is very little control over the precise temperature, humidity, pressure, gas composition, and other variables in each respective compartment. Thus, within each refrigerator or freezer compartment, the conditions are substantially uniform throughout the compartment.
Medications sometimes require refrigeration to maintain their effectiveness and to prevent spoilage. One option for such medication is to place the bottle in the refrigerator to provide temperature control. However, the refrigerator often is a high traffic area with access by children. Small medicine bottles may be knocked off the shelf, pushed to the back of the refrigerator compartment, or otherwise accessed by an unintended person.